Problem Statement Thousands of pounds of food waste are discarded on our campus every week. In the spring of 2011, a group of students conducted a week long Food Waste Audit in the campus dining hall. They found that nearly 7,000 pounds of pre- and post-consumer food was wasted. An estimated 91 tons of food waste is produced in our dining facility every year, the majority of which enters the municipal solid waste stream (MSW), while the rest goes through a garbage disposal and through the wastewater treatment facility (Coffey and Dodge 2010). By allowing this food waste to leave our campus through either of these routes, we are losing an important part of the organic waste stream, and its potential to add fertility to the soil in landscaping beds or the Student Garden on campus. When the campus produces over 400 tons of MSW each year (Facilities Data from Springer Waste 2011), food waste comprises at least 15% of our overall MSW. The amount of food waste being disposed of via the MSW stream from the student residence halls and apartments is unknown. Many students are neither conscious of the volume of waste that they accumulate individually in their apartments or residence halls, nor aware of the cumulative impact that it has in the overall waste stream. Failure to sustainably dispose of food waste significantly increases our environmental footprint. The total waste that must be transported from the college is larger than necessary, increasing fossil fuel emissions and waste that enters the landfill. Through the composting program that has been in place since the spring of 2011, we try to educate students on the importance of diverting food waste from wastewater treatment facilities and landfills, and build support for a future campus-wide program. Unfortunately, there is still a general lack of knowledge and
understanding of the system among students and areas of the process that require improvement, so we have spent the semester addressing these issues. Project Summary/Background In the spring of 2011, students worked with faculty and staff to establish a composting program that would take in food waste from one of the on-campus student apartment villages. This project was intended to be a pilot experiment to show the administration that students wanted an alternative to sending their food waste to the landfill and that a campus-wide system was desired. It is this program that we have worked to improve and expand this semester. The student apartment village from which we collect compost houses approximately 500 students. In the fall of this academic year, each of the 130 apartments was provided with a small bucket and a letter informing them of the program, what they should and should not compost and where to empty their buckets once they are full. The small buckets in each apartment can be emptied outside each of the 13 apartment buildings near the common laundry rooms in a larger bucket which is picked up weekly by composting volunteers. We use bicycles with attached trailers to carry the food waste from each building to the compost area. Because the food waste from each of the 10 apartments in a building all goes to one bucket, we do not know how each apartment is participating. However we have consistently weighed each building s bucket before adding it to the pile since the beginning of the program and thus know the total weight of food waste that is being diverted from MSW. We have conducted surveys of students at the end of the last two academic years to better understand the challenges and the perceptions the students may
have of composting, but because this is not a mandatory survey, while the data are helpful and instructive in understanding what changes make sense, they do not provide accurate statistics to understand how many students are participating. We were interested in experimenting with different methods of food waste collection, which required the purchasing of biodegradable bags, in an attempt to improve bucket cleanliness, and Bokashi bran, which was meant to act as a source of carbon and reduce odors while the bucket is in a student s apartment. We hoped that the implementation of these different processes would result in a behavior change in participating students and an increased amount of food waste being diverted from the apartment village, which would mean that less food waste would need to be transported from campus. The handout originally drafted by the students who began the program was wordy, outdated, and not effective in educating potential participants. This semester, we redesigned the handout, cutting the introductory letter completely and keeping the list of items that can and cannot be composted. We also made a specific handout for each of the new composting methods, explaining the differences of the new process. From surveys sent out to residents of the apartment village, we learned that participants were experiencing problems with cleanliness of the bucket as well as odor and fruit flies because the lids did not seal properly. We distributed new buckets designed specifically to hold compost to all of the apartments along with the individualized handouts. We also gave biodegradable bags to two buildings and Bokashi bran to two others.
By continuing to track the weight of food waste from each building and by sending an updated survey to each resident, we were able to get a better sense of participants feelings towards the different techniques and the program in general. Relationship to Sustainability While the Waste Reduction through Composting project is relatively small in relation to the overall goal of a campus-wide composting program, its success reflects that students continue to have an interest in a more sustainable campus. While some residents have admitted to giving little thought to issues of sustainability or in particular, where their food waste goes once it leaves their kitchen, we feel that through the composting program we are changing how students think about the waste stream. It is more sustainable for us to utilize the resource of thousands of pounds of food and yard waste generated each year to fulfill the needs of students and administration alike. By composting this waste, students have access to a nutrient rich supplement for the Student Garden, which produces fruits, vegetables and herbs that are sold to the dining hall during the summer. Also, funds otherwise spent by the college on fertilizers or trucking of waste may be saved. Eventually, were the composting program to be expanded even further, the end-product might be sold to local farmers or community members, generating income for our institution. As this project is on such a small scale, we cannot expect that our efforts will have an impact on the local environment, but we hope that it has made students more aware of more sustainable alternatives to what they are used to and change their behaviors as a result.
Materials and Methods On April 1st, 2011, student volunteers provided each senior on-campus apartment a small white bucket to put their compostable food waste in. The volunteers placed a larger bucket outside of each apartment complex. They also gave each apartment a flier with a list of compostable and non-compostable items and instructions to empty the smaller bucket into the larger one every week. Starting on April 8th, 2011, the volunteers collected the larger buckets, recorded the weight of the compost inside them, and emptied them into one of four 4x4x4-foot compost piles surrounded by wooden boards and a plastic roof. They added horse maneur and/or leaves to the piles, then turned the piles in order to promote aeration and microbial breakdown of the organic material in the compost. This process was repeated weekly for the rest of the academic year. We arrived at the institution and started composting as volunteers in September 2011, and along with other students, we continued the composting initiative for the 2011-2012 academic year, and are still composting during the 2012-2013 academic year. Throughout the initiative, when a pile either filled or had suitable soil, we gave it to the institution s Student Garden. In the fall of 2012, our team leader officially became compost manager. On October 12th, 2012, we began collecting coffee grounds from the campus dining hall twice per week, recording their weight, and adding them to our compost piles. We also distributed a large bucket to each apartment complex during that month. In the spring of 2013, Team Member #2 also became compost manager. On February 15th, 2013, we distributed new small buckets because the old ones were difficult for residents to clean, as well as new composting fliers. That day, we also
randomly selected two apartment complexes (using a random number generator) and gave each apartment in those complexes ten Bag to Earth bags. These bags are completely biodegradable, so when we collect them, we can put them into our pile and they will compost. We provided the selected apartments with fliers (in addition to the general composting fliers mentioned above) stating the bags benefits for the residents: lining the small bucket with a bag keeps the bucket clean. That same day, we also randomly selected two apartment complexes (separate from the ones receiving bags) and gave each apartment in those complexes a single bag containing approximately 0.831 pounds of Bokashi bran. Bokashi bran is made by fermenting material high in carbon (like wheat bran, sawdust, or wood shavings) with a liquid solution of water, microbes and molasses in an airtight container. The mixture is then dried and the microbes become dormant. The added carbon source helps balance the ratio of carbon to nitrogen in the compost piles. We provided the selected apartments with fliers stating the bags benefits for the residents: sprinkling the bran onto food waste reduces the food waste s odor. On March 25th, 2013, we emailed a link to an online survey to all (approximately 500) residents of the senior apartments. We collected 98 responses between March 25th and April 4th. We compared these responses to responses from previous semesters (Spring 2011 and Spring 2012). We would like to thank all of the compost volunteers for their help, as well as our advisor, a campus sustainability fellow, for assisting us with planning, distributing buckets, and collecting data.
Results, Evaluation, and Demonstration From the spring of 2011 to the spring of 2013, the composting initiative has collected 11,226 pounds of food waste (and counting) from our institution s apartments and dining hall, making our campus more sustainable. Resident participation did not seem to increase or decrease after we implemented the new programs. On average, we collected 110 pounds of food waste per week from the apartments (Figure 1). We also collected an average of 302 pounds of coffee grounds per week. Food Waste (lbs) 400 300 200 100 0 4/8/11 5/8/11 6/8/11 7/8/11 8/8/11 9/8/11 10/8/11 11/8/11 12/8/11 1/8/12 2/8/12 3/8/12 4/8/12 5/8/12 6/8/12 7/8/12 8/8/12 9/8/12 10/8/12 11/8/12 12/8/12 1/8/13 2/8/13 3/8/13 Week Figure 1 Amount of food waste collected from the apartments from April 8 th, 2011 to March 29 th, 2013. Breaks in the data are due to school vacations or days when we could not collect compost due to weather or lack of volunteers. Survey data indicate that resident participation in the composting program declined sharply between 2011 and 2012 before increasing slightly in 2013 (Figure 2), but there was likely a heavy response bias in 2011. In 2012 and 2013, the surveys came with the opportunity for respondents to win a free coupon for food at a local restraunt. This incentive did not exist in 2011, so a disproportionate number of respondents were probably already interested in composting. The responses in 2012 and 2013 are likely more realistic, but the response bias is almost certainly still there.
3% 6% 14% 13% 64% Figure 2 Survey responses to the question: How many people in your apartment are participating in the composting program? Left to right: 2011, 2012, and 2013 responses. Key: dark blue = All 4 residents; red = three residents; green = two residents, purple = one resident; light blue = no residents. Based on survey data, the bags seem to be the most effective method of composting. The most common problem that residents had with the regular composting program was the odor of the buckets. Six percent of respondents with Bokashi bran said that it doesn t reduce odor enough, while no respondents with bags had this problem (Figure 3). In addition, 0 respondents with bags felt that they don t keep the bucket clean, while 30% of respondents with the regular composting program felt that cleanliness was an issue. 40% 31% 25% 33% 11% 8% 10% 17% 15% 10% 6% 21% 23% 33% 25% 29% 24% 19% 17% 20% 25% 17% 41% Figure 3 The most common problems that respondents had with the composting program. Left to right: Problems with regular composting, biodegradable bags, and Bokashi bran. Keys: left (regular): dark blue = odor; red = cleanliness; green = fruit flies; purple = no problems; light blue = I can t get my roommates to cooperate. Note: These are only the most common problems and are not all of the problems that these residents had. Middle (bags): Too difficult to use; red = I don t have enough bags; green = The bag fills up too quickly; purple = no problems. Right (Bokashi): dark blue = It
doesn t reduce odor enough; red = I don t understand how to use it; green = I don t know how much to use; purple = no problems. A more obvious indicator that the bags were more effective than the bran was what we observed when we collected the compost. Apartments that received bags used them correctly, putting their food waste in the bags and placing the bags in the large buckets. Apartments that received Bokashi bran did not, taking the entire bag of bran that they received and putting it into the large bucket (with the bran still in the bag) along with their food waste rather than sprinkling it onto the compost in their small buckets. This implies that the bran is less intuitive and therefore is not likely to increase composting participation as much as the bags are. The Bag to Earth bags have societal and environmental benefits because they keep buckets clean, satisfying residents and potentially encouraging participation in the composting program. They have economic benefits as well; if we order a pallet of bags for next year, each bag will only cost 33 cents. At this price, if we distribute 20 bags to each apartment, it will cost our institution $1,716 per year. Bokashi bran may be cheaper in bulk, but dividing up the bran for each apartment would be labor-intensive and not worth the results when residents do not know how to use it. Therefore, we hope that we can increase the project s scale and distribute bags to all of the on-campus apartments in the future. At the exhibition event, we will present our findings in a poster. Conclusions Since its inception in April 2011, our compost initiative has successfully diverted a significant amount of food waste from MSW. However, we can divert more. One way to do this is through increasing resident participation. The results of our project support the distribution of biodegradable bags throughout the on-campus apartments. The bags solve
some of the biggest problems that residents have with the composting program, which could entice those residents to compost more in the future. They are also economically viable and easy to use, unlike Bokashi bran. However, further testing needs to be done. For example, if we are able to distribute bags to every apartment for a year, then we can compare the amount of weekly compost that year to the historical amount of weekly compost (110 pounds) and see whether there is an overall increase in diverted food waste. Our institution already supports our composting initiative because it is ongoing. This semester or over the summer, we will be building a new compost pile and receiving new bikes with which to collect the large buckets. If the institution supports the implementation of biodegradable bags, the school will benefit through the food that it receives from the Student Garden, and the environment will benefit as well. References Coffey, William & Dodge, Nadine. 2010. Composting at Skidmore College: Turning our Waste into a Resource. Environmental Studies Senior Capstone. Skidmore College, Saratoga Springs, NY. Available from: http://www.skidmore.edu/academics/wri/coffey_dodge.pdf Food Waste Audit. Murray Aikins Dining Hall, Skidmore College. March 2011. Springer Waste Inventory. Facilities Services, Skidmore College. 2011.